Pattayadoctor by Dr.Kijakarn

Category: Infectious

  • PostExposure medicines(PEP) for HIV

    PostExposure medicines(PEP) for HIV PEP =Post Exposure Prophylaxis for HIV typically consists of a 28-day regimen. Common regimens include:

    Tenofovir disoproxil fumarate (TDF) 300 mg + Emtricitabine (FTC) 200 mg + Raltegravir 400 mg twice daily (preferred for most exposures). – Alternatively, TDF 300 mg + FTC 200 mg + Dolutegravir 50 mg once daily (if raltegravir is unavailable or contraindicated). – For higher-risk exposures, boosted protease inhibitors (e.g., darunavir/cobicistat) may be added. – Rationale: Guidelines (e.g., CDC, WHO) recommend these regimens due to high efficacy and tolerability. – Effectiveness:
    If initiated within 72 hours of exposure, PEP reduces HIV transmission risk by ~80%. – Adherence to the full 28-day course is critical for effectiveness. – Rationale: Early initiation and adherence prevent viral replication and integration. – Side Effects:
    Common: Nausea, fatigue, headache, diarrhea (usually mild and transient). – Less common: Elevated liver enzymes, renal impairment (with TDF), or rash (with integrase inhibitors). – Severe: Rare, but monitor for hypersensitivity reactions or lactic acidosis (with older NRTIs). – Rationale: Side effects are generally manageable; dose adjustments or regimen switches may be needed.

  • Traveler’s diarrhea

    Definition: Traveler’s diarrhea (TD) is defined as the passage of ≥3 unformed stools in 24 hours, often accompanied by abdominal cramps, nausea, vomiting, or fever, typically occurring within the first 2 weeks of travel to endemic areas. –

    Etiology:

    Bacterial (70–80%): E. coli (ETEC, EPEC, EIEC, EHEC), Campylobacter, Shigella, Salmonella, Aeromonas, Plesiomonas. – Viral (10–20%): Norovirus, rotavirus, adenovirus. – Parasitic (5–10%): Giardia, Cryptosporidium, Entamoeba histolytica. –

    Risk Factors:
    Destination (high-risk: Latin America, Africa, South Asia). – Season (warmer months). – Dietary habits (street food, raw produce, contaminated water). –

    Prevention:
    Vaccination: No widely available vaccine; consider Dukoral (cholera vaccine) for high-risk travelers. – Chemoprophylaxis: Not routinely recommended; consider for high-risk groups (e.g., immunocompromised, inflammatory bowel disease). –

    Rationale: Risk of resistance and side effects outweigh benefits for most travelers. – Behavioral: Food/water precautions (avoid ice, uncooked foods, unpeeled fruits; drink bottled/boiled water). –

    Diagnosis:
    Clinical: Based on symptoms; stool culture not routinely needed unless severe (bloody diarrhea, fever, systemic symptoms). –

    Laboratory: Stool culture, PCR, or microscopy if symptoms persist >72 hours or severe.
    Traveler’s diarrhea (TD) is defined as ≥3 unformed stools in 24 hours with at least one symptom (abdominal pain, cramps, fever, nausea, vomiting). –

    Severity classification:
    Mild: <4 stools/day, no fever, no blood. – Moderate: 4–5 stools/day, mild fever, no blood. – Severe: ≥6 stools/day, fever ≥38°C, blood, or severe dehydration. –

    Management : Oral Rehydration and Salt Intake Essential for all cases; use oral rehydration solutions (ORS) or salty broths. –

    Rationale: Prevents dehydration, maintains electrolyte balance. –

    Treatment Options Mild cases: Symptomatic management (loperamide, bismuth subsalicylate). – Loperamide (4 mg initial, then 2 mg after each loose stool, max 16 mg/day). – Bismuth subsalicylate (2 tablets 4x/day). –

    Moderate/severe cases: Antibiotics (azithromycin 500 mg single dose, or ciprofloxacin 500 mg single dose). –

    Rationale: Reduces duration and severity; azithromycin preferred due to fluoroquinolone resistance in some regions. –

    Antibiotic Prophylaxis: Not routinely recommended; reserved for high-risk travelers (e.g., immunocompromised, inflammatory bowel disease). –

    Options: Rifaximin 200 mg/day or azithromycin 500 mg/week. – Special Considerations Children: Same as adults but adjust doses (e.g., azithromycin 10 mg/kg single dose). –

    Pregnancy: Avoid fluoroquinolones; use azithromycin or loperamide. –

    Bloody diarrhea: Stool culture indicated; consider invasive pathogens (e.g., Campylobacter, Shigella). –

    Prevention Food/water precautions: Avoid tap water, unpeeled fruits, undercooked meat. –

    Vaccination: No specific vaccine; consider typhoid vaccine for high-risk areas. –

    Follow-Up Persistent diarrhea (>1 month) warrants evaluation for parasitic infections (e.g., Giardia, Cryptosporidium)

  • Norovirus summary from Mikai

    Norovirus summary from Mikai Leading cause of outbreaks of gastroenteritis worldwide (~50% of reported outbreaks in the U.S.). –

    Predominantly transmitted via fecal-oral route; also present in vomitus. –

    Spread by asymptomatically infected individuals and symptomatic persons before symptom onset and for weeks post-recovery. –

    Prolonged viral shedding in immunocompromised individuals. –

    Pathogenesis:
    Exact cellular receptors and attachment sites under investigation. – Infects mature enterocytes in the small intestine, leading to villous atrophy and malabsorption. – Incubation period: 12–48 hours. –

    Clinical Features:
    Acute onset of nausea, vomiting, diarrhea (non-bloody), abdominal cramps, and low-grade fever. – Symptoms typically resolve within 2–3 days; dehydration is the main concern. –

    Diagnosis:
    Primarily clinical; stool PCR for confirmation in outbreaks. – Rapid antigen tests available but less sensitive than PCR. –

    Treatment:
    Supportive care (oral rehydration, IV fluids if severe dehydration). – No specific antiviral therapy; vaccination not yet available. –

    Prevention:
    Hand hygiene, proper food handling, and disinfection with bleach (1:10 dilution) due to virus stability. – No post-exposure prophylaxis. Rationale: Norovirus is a significant global health concern due to its high infectivity, rapid spread, and lack of specific treatments. Supportive care remains the mainstay of management.